Size is only part of the story. Density, speed, wind, roof type and roof age all decide whether a storm just bounced off your roof or broke it. Here's how it works — and why the only real answer comes from a trained inspector on your roof.
Hail about 1 inch (quarter size) and larger can damage most common roofs, especially asphalt shingles, wood and older roofs. Impact-rated and heavier systems usually take 1.75"–2"+ before they fail. Wind-driven or very hard hail can do damage below those sizes.
Two storms with the "same size" hail can do completely different damage. These are the forces at work every time a hailstone hits.
Bigger stones carry far more energy. Mass grows with the cube of the diameter, so doubling the size makes a stone about 8× heavier — and it falls faster too.
Hail isn't always solid ice. Clear, hard stones (near ice density) hit much harder than soft, cloudy, air-filled stones of the same size, which can crumble on impact.
Hail falls at terminal velocity — roughly 50 mph at 1" and 70+ mph at 2". Strong storm winds add sideways speed and can turn a small stone into a roof-breaker.
Straight-on hits transfer the most energy. Slopes facing the storm take the worst of it. Roof material, thickness, age, decking and insulation decide what fails.
Impact energy (kinetic energy) is what actually cracks shingles, fractures tile, punctures membranes and dents metal. Here's how fast it climbs.
| Hail size | Compare to | Fall speed | Energy | |
|---|---|---|---|---|
| ¾" | Penny | ~43 mph | 0.5 ft-lb | |
| 1" | Quarter | ~50 mph | 1.4 ft-lb | |
| 1¼" | Half dollar | ~56 mph | 3.5 ft-lb | |
| 1½" | Ping pong ball | ~61 mph | 7 ft-lb | |
| 1¾" | Golf ball | ~66 mph | 13 ft-lb | |
| 2" | Hen egg | ~71 mph | 23 ft-lb | |
| 2½" | Tennis ball | ~79 mph | 56 ft-lb | |
| 3" | Teacup | ~87 mph | 115 ft-lb | |
| 4" | Softball | ~100 mph | 364 ft-lb |
Approximate values for solid, round ice (density ≈ 0.9 g/cm³) falling at terminal velocity in still air. Real hail is often less dense; wind-driven hail can hit harder. Speeds and energies are estimates for education, not a damage determination.
Going from 1" to 2" hail means roughly 16 times more energy hitting your roof. Going to 3" is about 80 times more.
That's why a "little hail" can leave a 20-year-old shingle roof needing replacement, while golf-ball hail might leave a Class 4 impact-rated roof with only cosmetic marks.
It's also why hail reports for your zip code aren't enough. Hail size changes block to block. What landed on your roof — and what it did — has to be confirmed on the roof itself.
General guidance from published damage thresholds. Roof age, condition, installation and wind can lower these numbers. Only an on-roof inspection can confirm damage.
These are typical sizes where real, functional damage starts showing up — damage that shortens the life of the roof or lets water in. Older and weathered roofs fail sooner.
Hail damage usually doesn't leak right away. Bruised shingles and fractured membranes break down over months — often after a claim deadline has passed.
Most hail damage is invisible from the yard. Bruises, hairline tile cracks and anvil strikes take hands-on testing up on the roof.
Hail size varies across a single street, and wind-driven hail hits harder than its size suggests. What you saw in the yard isn't always what hit the roof.
Class 4 means a roof passed a lab test — not that it can't be damaged. Big storms, repeat storms and aging all still take their toll.
Hail maps and size charts are a starting point. The only way to know if your roof was damaged is to have trained roofing professionals get on it, test it and document it — so it holds up to anyone who asks.
Fill out the form or call/text the team. We'll set a time that works for you.
We get on the roof and check every slope, material and penetration for hail and wind damage.
Photos, test squares, collateral damage and measurements — documented the right way.
We show you exactly what we found and explain your options, with full attention on you.
SkyView is a team of roofing experts with 25+ years of hands-on storm experience — residential and commercial, nationwide. Our inspections are for free.
